Almanac--a book of dates, facts, statistics

Atlas--a collection of maps

Database--a file of digitized information accessible online

Dictionary--very brief explanation of terms

Encyclopedia-- summary information on a variety of topics

Journal--a periodical of current research

Magazine--a popular interest periodical  

Periodical--serial publication including journals & magazines 

Primary Source-- document or record containing first hand information or data

Secondary Source--a work summarizing, analyzing, or evalu-ating a primary source

Tertiary Source-- a work based solely on secondary sources 

Thesaurus--a book of synonyms